Verification Case 16
PRODUCT: AFT Impulse 9
TITLE: ImpVerify16.imp
REFERENCE: Waterhammer Analysis, John Parmakian, Dover Publishing, 1963, Page 75 - 86.
FLUID: Unspecifed. Specific gravity is 1.155. Viscosity is not relevant because friction factors are assumed. Liquid bulk modulus is not relevant because all wavespeeds are specified.
ASSUMPTIONS: Parmakian assumes the pipes are frictionless. The Impulse model assumes the friction factors are very small (0.001). The specific speed of the example pumps was 0.79 (2160 gpm units). The four quadrant data set from Kittredge of 0.71 (1935 gpm units) was assumed. Neglect cavitation.
From Parmakian’s Figure 56 on page 86, it was estimated that the pump discharge elevation was 36 feet and that the pipe traveled horizontally for 1000 feet before rising to the discharge reservoir. It was also estimated that the pipe entered the discharge reservoir at 200 feet.
RESULTS:
DISCUSSION:
Parmakian obtained these results using graphical waterhammer methods.
The specific speed of the example pumps was 0.79 (2160 gpm units). AFT Impulse has a data set from Thorley for exactly this specific speed. But agreement with the predictions was marginal and is not shown. The next closest specific speed of 0.71 (1935 gpm units) gave very good agreement and is shown above. The classic data from Donsky for specific speed of 0.46 (1270 gpm units) was also ran and gave good agreement (but is not shown).
